The invention relates to a conveyor chain and a conveyor for gripping and conveying paper material.
In U.S. Pat. No. 6,241,648, a conveyor chain composed of hingedly connected links is disclosed of which some of the links each have a first grip member having a first grip surface. The first grip members are each movable back and forth relative to a second grip member between a gripping position for holding paper material and a retracted position for releasing the paper material. The first grip members are formed of spring-steel plate and the second grip members are made of a plate material harder than the plate material of the first grip member.
A disadvantage of such a chain is that manufacturing of the chain is quite complicated and accordingly costly. Moreover, steel chains tend to be relatively noisy when circulating in operation, which is a particular disadvantage if the conveyor is to be used in or close to an office environment.
In U.S. Pat. Nos. 3,915,447, 4,647,032 and 5,156,393, conveyor belts for gripping sheets and conveying gripped sheets are disclosed. While manufacturing costs of such belts appear to be lower than the manufacturing costs of chains equipped with grippers, engagement of the sheets tends to be less positive and relatively much friction is involved in controlling flaps of the belts for gripping and releasing sheets when required.